1. Field of the Invention
This invention relates to heat exchangers and, more particularly, to apparatus for providing thermal isolation and support of heat exchanger ducting members from the heat exchanger frame.
2. Description of the Prior Art
Arrangements are known in the prior for fastening together two different elements in a heat insulating mounting or for accommodating thermal growth between adjacent elements which are mounted together. For example, the Ygfors patent, U.S. Pat. No. 3,690,705 discloses a device for rigidly connecting two metallic members together in heat-insulating relation. The arrangements disclosed in this patent depend upon a bushing constructed of a material having known heat insulating properties mounted between the two members.
The Young patent, U.S. Pat. No. 3,710,853, discloses an arrangement of a radiator comprising two headers or tanks on opposite sides of a heat exchanging core. One of the tanks is fixed to the frame while the other is mounted to the frame by means of a shoulder stud extending through an enlarged hole in the frame to permit lateral movement of the stud. However, no thermal isolation of the radiator from the mounting frame is provided, the only concern being the accommodation of the different coefficients of expansion for the frame and the radiator. The arrangement of the Young patent depends upon flexible conduits, typically rubber hoses, for connection to the fluid passages of the radiator.
Devices of the type disclosed in these prior art patents may be suitable for apparatus of limited size, weight and thermal gradient. However, they are totally unsuitable for heat exchangers of the type here involved which include heat exchanger cores operating at temperatures in excess of 1000.degree. F. supported in frames of conventional structural steel construction maintained at temperatures less than 150.degree. F.